Hello I am new to the forum, I couldn't find any thread that delt with these problems as a whole, and they act very differently when they are put together in one program.

I have a design expo on saturday and I am in some urgent help.

BACKGROUND: I am building a camera mechanism that is automatically panning and controlled by a two button controlled servo. I want this device to automatically pan to 180 and back to 0 continuously until a button is pressed. Once a button is pressed(left or right) I want the servo to pan in the coinciding direction. Then i want the position of the servo to stop if the button was not pressed anymore, and then after a certain amount of time, have the automatic panning start back up.

OVERVIEW:My code is in a case structure format. Case 0 is the automatic panning to the right, Case 1 is the automatic panning to the left. During both of these cases the code looks to see if any of the buttons are being pressed If they arent, they switch between each other, if a button is being pressed then the code changes the casenumber and breaks the loop.

Case 2 is for when the leftbutton is pressed and it pans left for that amount of time, Case 3 is the same thing but for the right button. In both of these cases I am looking to see when the button stops being pressed. If it is the servo should stay in its current position for some arbitrary time. I made an if statement that test to see whether the "current time" - the "previous time" is greater than the interval and if it is it should break to the automatic.

However, my code seems to think this is always true and immediately breaks out of the loop, essentially making not delay

Servo myservo;const int leftbutton = 2; //variable to represent the pin that the left button is onconst int rightbutton = 4; //variable to represent the pin that the right button is onint casenum = 0; //case number to tell the servo which case to runint pos = 0; //positionint delaytime = 20; // increasing this slows down the servo movementunsigned long previousmillis = 0; // last time updateint interval = 2000; // interval at which to do something (milliseconds)

void setup(){

myservo.attach(9); // attaches the servo on pin 9 to the servo object

pinMode(leftbutton, INPUT); // the buttons are the inputs pinMode(rightbutton, INPUT);

}

void loop(){ unsigned long currentmillis = millis(); if (digitalRead(leftbutton)) //checks to see if each button is being pressed { casenum = 2; //if so it switches the casenum } if (digitalRead(rightbutton)) { casenum = 3; }

myservo.write(pos); // Move to next position delay(delaytime); // Short pause to allow it to move if (digitalRead(leftbutton)) //checks to see if each button is being pressed { casenum = 2; //if so it switches the casenum break; } if (digitalRead(rightbutton)) { casenum = 3; break; } }

casenum = 1; //if none of the buttons are pressed then it goes to pan left break;

case 1: for(pos = pos; pos >= 0; pos -= 1) // pan left {

myservo.write(pos); // Move to next position delay(delaytime); // Short pause to allow it to move if (digitalRead(leftbutton)) //checks to see if each button is being pressed { casenum = 2; //if so it switches the casenum break; } if (digitalRead(rightbutton)) { casenum = 3; break; }

} casenum = 0; break;

case 2: while (digitalRead(leftbutton)) //while the button is being pressed { myservo.write(pos); //rotates servo to its current positon delay(delaytime); pos-=1; //position becomes one less } myservo.write(pos); //after the button stops being pressed the servo is at pos if(currentmillis - previousmillis >= interval) //if the total time - the start time is greater than 3 sec { casenum = 1; //this is where the code goes wrong, it seems like it reads this if statement //and immedietly say thinks its true previousmillis = currentmillis; break; } if (digitalRead(rightbutton)) { casenum = 3; break; } if (digitalRead(leftbutton)) { casenum = 2; break; }

Your problem is that you are only ever setting previousMillis in the beginning of the code and when the 3 seconds have been reached, so rather than measuring the time since the button was released, you're measuring the time since the start of the program the first time, and the time since you went back to your automatic mode each subsequent time. I would change the name of previousMillis to lastTimeButtonWasPressed. That should give you a better idea of where you should be updating it.

however isn't it changing in my loops when I say previousmillis = currentmillis

Because you only ever set it when you say "the button has been released long enough for me to go back to state 0 and state 1".

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And can you elaborate on the lastTimeButtonWasPressed, I think I might get what your saying but its cloudy

In how you want it to work, previousMillis should be set based on the state of the button (or more specifically, you want it to be set on the transition). As it stands now, there is no link between when previousMillis is set and the state of the button. I suggested changing the name to show that they should be related, as well as give you a hint on where it should be being set.

So now that I want my function to know when the last time I pushed the button, I should put it under the my while "button is being pressed loop" So then once the button stops being pressed it takes the time at that point.Something like this?Top Code:

Servo myservo;const int leftbutton = 2; //variable to represent the pin that the left button is onconst int rightbutton = 4; //variable to represent the pin that the right button is onint casenum = 0; //case number to tell the servo which case to runint pos = 0; //positionint delaytime = 20; // increasing this slows down the servo movementunsigned long LastTimeButtonWasPressed; // last time updateint endTime = 2000; // interval at which to do something (milliseconds)

case 2: while (digitalRead(leftbutton)) //while the button is being pressed { myservo.write(pos); //rotates servo to its current positon delay(delaytime); pos-=1; //position becomes one less } LastTimeButtonWasPressed = millis(); myservo.write(pos); //after the button stops being pressed the servo is at pos if(currentmillis - LastTimeButtonWasPressed >= endTime) //if the total time - the start time is greater than 3 sec { //casenum = 1; //this is where the code goes wrong, it seems like it reads this if statement //and immedietly say thinks its true //previousmillis = currentmillis; //interval = millis() +; break; }The comments are there because I am not sure what to do with that code.

case 2: while (digitalRead(leftbutton)) //while the button is being pressed { myservo.write(pos); //rotates servo to its current positon delay(delaytime); pos-=1; //position becomes one less LastTimeButtonWasPressed = millis(); } myservo.write(pos); //after the button stops being pressed the servo is at pos

case 2: while (digitalRead(leftbutton)) //while the button is being pressed { myservo.write(pos); //rotates servo to its current positon delay(delaytime); pos-=1; //position becomes one less } myservo.write(pos); //after the button stops being pressed the servo is at pos previousmillis = millis();

if(millis() - 5000 >= 3000UL) //if the total time - the start time is greater than 3 sec { //casenum = 1; //this is where the code goes wrong, it seems like it reads this if statement //and immedietly say thinks its true //previousmillis = currentmillis; //interval = interval + millis(); break; }The code paused. But only for around 5 seconds.There is also a time slot where it will delay and then it will just stand still after I press the button and I am trying to get the significance of this, but I just can't figure it out

while (digitalRead(leftbutton)) //while the button is being pressed { myservo.write(pos); //rotates servo to its current positon delay(delaytime); pos-=1; //position becomes one less } myservo.write(pos); //after the button stops being pressed the servo is at pos previousmillis = millis();

if(millis() >= 8000UL) //if the total time - the start time is greater than 3 sec { //casenum = 1; //this is where the code goes wrong, it seems like it reads this if statement //and immedietly say thinks its true //previousmillis = currentmillis; //interval = interval + millis(); break; }

but for the second part, I thought the same thing, but with the -5000 on the left side of the inequality delays the panning for 5secs which doesn't make since to me

case 2: while (digitalRead(leftbutton)) //while the button is being pressed { myservo.write(pos); //rotates servo to its current positon delay(delaytime); pos-=1; //position becomes one less LastTimeButtonWasPressed = millis(); }

I want the first code to become a timer. When this the total time - the time from when the button was last pressed is greater or equal to 3secs I want the code to pan automatically.

My overall idea with the conditionally breaks is that if the code reads that the leftbutton is being pushed it should rotate left and stay left once the button is not pushed. However, if either of the buttons are pushed again, I want it to restart the case and essentially restart the "delay" time.

I want the first code to become a timer. When this the total time - the time from when the button was last pressed is greater or equal to 3secs I want the code to pan automatically.

So you have the conditional part down, but if the condition fires, all you do is break out of the code to just go right back into it. How does that break statement make "the code pan automatically"?

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My overall idea with the conditionally breaks is that if the code reads that the leftbutton is being pushed it should rotate left and stay left once the button is not pushed. However, if either of the buttons are pushed again, I want it to restart the case and essentially restart the "delay" time.